// TRFMath.cpp

#include "TRFMath.h"

using std::fmod;
using std::asin;

namespace trf {

double PI = 3.141592653589793;
double TWOPI = 2.0*PI;
double PI2 = 0.5*PI;

double CLIGHT = 2.99792458e10;

double BFAC = 1.0e-13 * CLIGHT;

// Fix 30jan98 to add fabs(range) instead of range.
// Previous gave bizzare behavior for negative ranges.
// Now sign of range has no effect.
double fmod1( double value, double range ) {
  double tmp = fmod(value,range);
  if ( tmp < 0.0 ) return tmp + fabs(range);
  return tmp;
}

//**********************************************************************

// asinrat = asin(x)/x

double asinrat(double x) {
  double small = 1.e-3;
  if ( fabs(x) < small ) {
    double x2 = x*x;
    return 1.0 + 1.0/6.0*x2 + 3./40.*x2*x2;
  }
  else {
    return asin(x)/x;
  }
}

//**********************************************************************

}  // end namespace trf